Electric current rectifying device and method of making the same



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M.LAZARUS- ELECTRIC CURRENT RECTIFYING DEVICE AND METHOD OF MAKING THE SAME Filed Sept. 26, 1935 jig April 7,1936.

ATTORNEY i maar A,... 7, N1936 y.2,036,707

. the accompanying drawing, or by any mechaniportions of the iilm or layer of cuprous oxide on prises a tapered pin. maybe also reduced at said portions-as by quench- UNITED sTATEs PATENT oFFlcl-z ELECTRIC 'CURRENT RCTIFYING DEVCE AND METHOD 0F MAKING THE SAME Meyer Lazarus, Brooklyn,I N. Y. l Application September 26, 1935, Serial No. 42,204

s claims. (ci. 17a-fasc) My invention relates to improvements in elec- Fig. 5 is an axial section of another form of `tric current rectifying devices and the method my rectifyingfelement showing part of the metal of making the same, and it consists in the novel pin, which is hereinafter described, in elevation. features which are hereinafter described. Fig. 6 is a front elevation of a series of elements One of the objects of my invention is to proof the form of my rectifying device which is duce a perfected current rectifying device for shown in Figs.'1 and 2. I converting alternating current into direct cur- Fig. 7 is a longitudinal axial section of an rent. assembly of elements or stack in the form of my Another lobject is to have my rectifying device rectifying device which is shown in Figs. 1 and 2. suitablefor charging storage batteries. Fig. 8 is a front elevation of an element, such 10 A further object vof my invention is to have my as shown in Figs. 1 and 2, showing the gradual rectifying device adapted also for small currents, decrease in the size of the crystals of the cuprous such as for the circuits-of electric meterstand oxide from the wider end of the element to the other electric instruments. narrower end thereof.

A still other object is to produce a new cuprous Fig. 9 is an end view showing a way of stack- 15 oxide rectifying element that will rectify higher ing lrectifying plates Il, such as shown in Figs. voltages, than' has been possible heretofore. 1 and 2';

Another object is to reduce the ageing of the Fig. 10 is an end view of theassembly of elerectifying device by reducing the number of conments, which is shown in Fig. '7. tacting electrodes which are applied to the cu- Fig. 11 is a side elevation of an assembly 0f 20 prous oxide, -as is hereinafter described. my tapered-pin shaped elements connected in the A further object of my invention isto reduce form of a Wheatstone bridge full Wave circuit to a minimum the stacking of rectifying elefor supplying unidirectional current to ameasurments by elongating the elements for an ining instrument. crease in a given voltage. y In Figs. 1 and 2, 11 designates a taperedi plate, 25

A still other object is to control the sizes of the preferably 0f COPPE?. Which iS Shown RS BOVered crystals o cuprous oxide of my rectifying eleon the surfaces I2 of both sides thereof by a lm ments. y l or4 layer of cuprous oxide.

Another ob'ject is to pass the electric current, A copper alloy, such as an alloy of copper and i which passes through my rectifying device, Iover .silver or of copper and zinc, may beused instead 30 an extended distance whereby the elements are of copper; the Plate Il Will then' be cveled by enabled to withstand a higher surge without-be a film or layer of the compound of the metal.

ing destroyed or damaged. Fig. 2 shows also a layer of cupric oxide super- A further object is to have my rectifying deimposed over part of the'lm of cuprous oxide, vice compact, simple, durable, rugged and relafor a purpose which is hereinafter described. 35

tively inexpensive. The surface I2 of only, one side of the plate Other objects and advantages will hereinafter II may be-covered by a lm 01 layer 0f CUDIOUS appear. oxide, if desired. l

I attain these objects by the electric current Relatively large contacting electrodes I 3 and rectifying device and the method of making the Y relatively small contacting electrodes I4 of some 40 same, several forms of which are illustrated in soft metal, such as-lead or tin, arev pressed against cal, physical or electrical equivalents or obvious the surface or surfaces I2 atvthe opposite ends modifications of the same. of the plates IIl for conducting a' current there- In the drawing Fig. 1 is a front view of an elethrough along the nlm or films of cuprous oxide 45 ment of one form of my rectifying device. .on the surface or surfaces I2.

Fig. 2 is a sectional edge view of the element Electrodes made of other substances, such as Vshown in Fig. 1, on the line 2.-,2 of-Fig.1. graphite, may be used at the above described Fig. 3 is a front elevation of another form portions at the ends of the plate II.v of an element of my rectifying device, "which com- Part of the cuprous oxide at the surfaces I2 50 Fig. 4 is a view onthe line 4 4 of Fig. 3 ing the ends of the plate II by means of a reshowing the film or layer of cuprous oxide in secducing reagent such as a solution of alcohol lor tion; and showing the metal pin, which is hereoil, for said portions to serve as electrodes. inafter described, in elevation. Where both 4sides of the plates II are oxidized' 55 I provide thin metal bands I 6, to connecta the pairs of electrodes I2 on the opposite sides of the plates I'I at the wide ends thereof and bands Ilia to connect the electrodes I4 at the narrow ends of the plates II, as shown in Figs. 2 and 7.

Metal strips I'I are shown in Fig. 7 as connecting the bands I6 to the bands IGa of adjacent plates II.

A bracket 25 is shown in Fig. 7 as supporting the assembly of rectifying elements |I-I2, which are arranged as in Fig. 9` and are shown as clamped between a pair of terminal plates 26, which may be of iron, by means of a screw 21 at one end of the assembly and a pair of pins 28 at the other end thereof.

Insulating discs 29 are shown in Fig. 7 at the end of the stack; to insulate the latter from the bracket 25 and the plates 26.

Sheets I8 of insulating material are shown in Fig. 'I as placed between adiaeent plates II, with the electrodos I3 and I4 and the bands I6 and Ita thereon.

Instead of employing the sheets I8, the greater part of the surfaces of the plates I I--I2 between the electrodes I3 and I4 may be left covered by black cupric oxide I8a, which is shown in Figs. 1 and 2 and is formed thereon during the process of oxidation, and the cupric oxide may be removed from the portions where the velectrodes I3 and I4 engage with the cuprous oxide on the plate Il. The bands I6 and |6a may then be insulated from each other by suitable strips of insulating material.

Wire connections I9 are shown as made at the ends of the stack in Fig. 7 and at the end of an element in Figs. 2 and 3. v

The connections I9 may be made otherwise than as shown.

lWhen a current is passed through the connection I9 it readily flows along the films of cuprous oxide on each plate II from the electrode I2 to the electrode I4; but a flow in the opposite direction is obstructed; whereby an asymmetric eii'ect is produced.

The voltage of my rectifier is governed by the length of the plate II of each element and by the number oi.' the elements in series in a stack.

The metal plate II of each element serves as a carrier or support for the film or layer of cuprous oxide on the surface I2 of the element.

In the modification of my rectifier, which is shown in Figs. 3 and 4, a tapered pin 2|, which is made of` an element of copper, is used instead oi.' a plate II; the pin 2| may be either conical, pyramidal or have any other shape, if desired.

The relatively large electrodes 23 and the relatively small electrodes 24 are applied to portions of the film of cuprous oxide at the two ends of the pin 2 I, which is covered by said nlm on the surface 22 thereof.

In the modication of my rectifying device, which is shown in Fig. 5, a pin 2| is. employed, which is similar to the pin 2| of Figs. 3 and 4, and is provided at the wide end thereof with a cavity 20, which serves to produce coarser crystals of cuprous oxide on the adjacent surface 22 of the pin 2| when the wide end of the latter is quenched in a cooling fluid.

The crystals on the surface 22 of the pin 2| are thereby arranged in a gradually and successively ner grading of size from the wider end towards the narrower end of the said pin 2|.A

The electrodes 22 and 24 of Fig. 5 are similar to the electrodes 22 and 24 of Figs. 3 and 4.

Fig. 6 shows a side view of an of rectii'ying elements I||2 disposed in series in the same plane. 'Ihe electrodes I3 of the elements II-I2 are shown as connected to the electrodes I4 of the adjacent elements by means of connecting wires or strips Ila.

The wire connections I3 are attached to the electrical terminals of the series.

Fig. 8 shows the successive gradation of the size of crystals on the surface 42 of an element 4I, which is similar to the element II-IZ of Figs. 1 and 2.

'Ihe successive grading of the size of crystals on the surface 42 proceeds from the Wider end of the element 4I to the narrow end thereof and is produced by rst heating the element 4I to a bright red heat, then partly cooling it in air to a desired lower temperature and then quenching the wide end of the element 4I in a `cooling liquid leaving the remaining portion of the element to be gradually cooled by the air.

'I'his gradation assists to check the back flow of the current from the narrow end towards the wide end of the element 4I.

An ear 43 and a neck 44 are provided at the' narrow end of each of the elements II and 4I as shown in Figs. 1 and 8; the ear 43 serves as an electric terminal, and is shown as not very large; but I do not restrict myself to the size thereof as shown and the neck 44 is made as small as possible without being overheated by the current flowing therethrough.

Rectification may also be accomplished by the narrow neck 44 near the narrow end of the tapered element II or 4I regardless of the relative sizes of the contacting electrodes, to check the back flow of the current into the element.

Fig. 9 shows a way of stacking elements I I-I 2' of Figs. 1, 2 and '1.

It will be understood that the lm or layer of cuprous oxide in all the above described modications of my rectifying device is too thin to be 'self sustaining and requires a metal support or carrier; but I do not restrict myself to any particular thickness of the lm or layer.

Variations are passible, and parts of my invention may be used without other parts.

I do not, therefore, restrict myself to the details as shown in the drawing.

I claim as my invention and desire to secure by Letters Patent:

1. In an electric current rectifying device a carrier made of a. copper element, a layer consisting mainly of cuprous oxide, 'on the surface of 'said carrier and contacting electrodes applied to the said layer on the opposite ends of said carrier. one of the said electrodes having a relatively large area of contact with said layer and the other of said electrodes having a relatively small area of contact with said layer, the electrode having the said larger area of contact to receive a current, and the other of said electrodes to discharge the current, and said oxide permitting said current readily to iow from the electrode having the said larger area of contact to the other electrode, and said oxide obstructing the flow of said current in the opposite direction.

2. In an electric current rectifying device a tapered carrier made of a copper element, a layer consisting mainly of cuprous oxide on the surface /of said carrier and a pair of contacting electrodes /of unequal size applied to the said layer at the opposite ends of said carrier, the relatively large electrode at the wide end of the carrier to receive a current and the relatively small electrode at thenarrowendofthecarriertodischargethe current, said oxide permitting said current readily to iiow from the wide end-of the carrier to the narrow end thereof, and said oxide obstructing the flow of said current from the narrow end of the carrier to the wide end thereof.

3. The elements of claim 1, said oxide having a crystalline formation, and the crystalsthere'oi? the shape of a tapered pin, the tapered surface` thereof being covered by said lay'er and said electrodes being applied to said layer at said ends.

6. The elements of, claim 1, said carrier having the shape of a tapered pin, the" tapered surface whereof is covered by said layer, said electrodes being applied to said layer at said ends, said pin having a cavity formed at the wider end thereof coaxially with said pin, said oxide having a crystalline formation and the crystals thereof being successively graded in size on the said surface in the direction from the wider end of said pin .to

4 the narrow end of the latter, and said cavity being disposed to assist during the operation of quenching in having said crystals arranged with the coarser crystals'near the wider end of the said pin. w

'1..In an electric current rectifying' device a tapered carrier made of a copper element, a layer 4consisting mainly o! cupi-ous oxide on the surface of said carrier a pair of contacting electrodes applied to the said layer at the opposite ends of said carrier. the electrode at the wide end of the carrier to receive a currentand the electrode at the narrow end of the carrier to discharge the current, said oxide permitting the current readily to now therealong from the wide end of the car- ,rierl towards the narrow end thereof, and said oxide obstructing the flow of the current from the narrow end of the carrier towards the widev end thereof.

i 8. The elements of claim 7, said carrier having thereon at the narrow end thereof an enlarged ear and a small neck positioned inwardly of said ear, said ear having one of said electrodes applied thereto, and said neck serving to obstruct the flow of the current from the electrode lon said ear toward the other electrode ina direction from the narrowend of the carrier towards the wide end thereof.

9. An asymmetric conductor comprising a tapered carrier made of a copper element, a layer consisting mainly of cuprous ovide on the surface of said carrier, a pair o f contacting electrodes applied to the said layer at the opposite ends of said carrier, the electrode at the wide end of the carrier to receive a currentand the electrode at the narrow end of the carrier to discharge the current, said oxide permitting the current readily to flow therealong from the wide end of the carrier towards the narrow end thereof and said t oxide obstructing the flow of the current in the portions of the layer of cupric oxide being omitted to provide contacting areas for the said contacting electrodes, said layer of cupricl oxide serving to insulate the said carrier from adjacent similar carriers when assembled withthe latter Into a series.

Y MEYER LAZARUS.

opposite direction, and a superimposed layer of cupric oxide on the said layer of cuprous oxide, 

